Is there any secondary benefits to learning to fly a f16? Like, does it make flying something else easier as it gets them used to something more modern?
US fighter jets from the 70s to 90s have fairly similar general layouts compared to one another. I can't imagine they'd get anything besides the F16 though from us since it's relatively affordable, maintainable, exportable, and really good.
The US is almost certainly encouraging other countries to donate their F-16s to Ukraine in exchange for buying F-35s at a discount. This has a ton of benefits. It generates new sales (both today and in the future via maintenance contracts) for US produced equipment, it gets Ukraine much-needed lethal aid, and it upgrades the air force of various NATO countries.
The pilots will be bringing home American doctrine, and be introduced to a wider array of weapons, tactics, and networking technology. Most importantly, in my opinion, the Soviet technology bubble has been broken and Ukraine will gain 21st century air power.
the Soviet technology bubble has been broken and Ukraine will gain 21st century air power
This is a big deal. They will be able to data link with NATO-provided AA systems like Patriot, as well as American operated AWACS flying over the Black Sea. Situational awareness is a big deal for survivability; this will be a huge upgrade for them.
It also enables the use of a whole host of new munitions. No longer will NATO munitions need to be retrofitted to a Su-34 or MiG-29 with reduced capability, but instead can be attached directly to the F-16 which already knows how to use them. The F-16 is one of the most popular export aircraft, so the work has already been done to get a wide array of munitions working 100% with it.
The main benifit of flying a f16 is the weapon loadouts and sensor cooperation. The plane is primarily as target identifier and the missile does the rest.
That depends, if this is your first plane you learn a lot of general flying. However if you can already fly all you are learning is how this one airplane is different. In an emergency you need to know how your plane will react as you need to have the right reactions for trouble which is different in different airplanes, so if this is your second plane there isn't nearly as much gain.
Likewise, if this is your first military jet you also learn fight tactics. However if you have already flown a military plane you know that. Here there is something to learn though as there are some NATO standard controls that would apply to other planes but not the airplanes they have had before . (Ukraine has rigged up some air to air missiles to work from MiGs, but with proper integration there are controls Ukraine hasn't had the ability to use before that they now get to learn.